Perth’s scheme to replenish groundwater to drought-proof the city

A city in Australia, is drought-proofing themselves against climate change by replenishing the underground aquifers that provide their drinking water with recycled water.

The Environmental Protection Agency (EPA) recently approved an application for the water authority in Western Australia to double its Gnangara Mound groundwater replenishment capacity to 28 gigalitres a year.

This proposal would see the Water Corporation build a 12.8-kilometre-long pipeline from a proposed recycled water plant at Beenyup in the northern suburbs to two separate aquifers, which will then lead to the Leederville and Yarragadee aquifers.

An estimated 14 gigalitres of wastewater would be processed and treated to meet potable standards at the new facility in Beenyup annually. At the same time, another 14 gigalitres will be taken from the aquifers every year for treatment to be used as drinking water.

“It is not a bad thing because any time we talk about water, we should be interested in the water we are getting and the quality we are getting,” Professor of desalination and water treatment at Murdoch University, Wendell Ela, said to the Guardian Australia.

Ela added that aquifer was a “very large, very cheap storage tank” that enables the Water Corporation to replace groundwater at a steady rate while also allowing water extraction when needed.

“You want it to essentially be a net zero balance,” he explained.

Water Corporation spokeswoman Clare Lugar said that the scheme to replenish groundwater resources is a part of a long-term plan to secure a supply of water in the face of climate change. However, there is also a third part to the plan – encouraging people to use less water.

“Groundwater replenishment ticks two of these boxes – increasing water recycling and developing a new source,” Lugar said. “It is a climate-independent source of water, and the new plant at Beenyup will have the capacity to supply the same amount of water used by 100,000 homes each year.”

The groundwater replenishment scheme is part of a project aiming to make Perth’s water supply “climate independent” by 2022. According to a report the EPA released, Perth is estimated to experience a supply gap of 70 gigalitres per year over the coming decade.

By 2060, a fifth of Perth’s water supply is anticipated to be replenished groundwater.

Construction of the proposed project will begin in July 2017.


Source: Guardian Australia